1. Field
This disclosure relates to a graphene sheet, a graphene base including the graphene sheet, and highly efficient methods of preparing the graphene sheet and the graphene base, whereby multiple graphene sheets may be simultaneously formed directly on a substrate. The graphene sheet may have a large size, fewer defects, and improved quality relative to commercially available graphene.
2. Description of the Related Art
Generally, graphite has a structure in which planar, two-dimensional (“2D”) graphene sheets are stacked parallel to each other to form a three-dimensional crystalline material. Each graphene sheet includes carbon atoms linked to each other in a hexagonal configuration. Recently, extensive research on graphite has shown that graphene sheets, which were separated from graphite, have very useful characteristics and are unlike other materials. For example, the electrical characteristics of graphene are anisotropic, and thus depend on the crystallographic orientation of the graphene. The anisotropy enables selection of the electric characteristics by using graphene in a selected direction. Thus, a device having selected electrical characteristics may be provided by using the graphene in a selected crystallographic orientation. Graphene sheets are therefore useful for carbon-based electrical devices or carbon-based electromagnetic devices.
However, currently it is difficult to prepare a large-sized graphene sheet with sufficiently few defects, and it is even more difficult to directly form such a graphene sheet on a substrate without transferring the graphene from another material. Thus there remains a need for a large graphene sheet having fewer defects, and a method of forming the graphene sheet which avoids transferring the graphene sheet, such as transferring the graphene sheet from a material on which it is formed to a substrate for a device, for example.